You know how the Gems seem to have warp pads set up all around Earth? They must be pretty well-traveled, and it would be weird if depictions of them didn’t show up in archaeological records, legends, and ancient ruins here and there.
Seriously, imagine. Nearly all the native cultures of the Americas, from the Nazca to the Maya to the Inuit have some kind of story handed down throughout generations about four mysterious gem women.
Egyptian wall carvings of the gems along with hieroglyphs telling of their exploits.
Ceramic Greek pots with depictions of the gems defeating the ‘legendary’ monsters of ancient Greek mythology.
Old scrolls long hidden away in Chinese libraries speaking of the four great gem warriors that could defeat any man in battle and had supernatural powers.
Australian Aboriginal rock art and bark paintings of women that somehow seem different from normal depictions of people, doing things that would be impossible for human beings.
The gems appearing as carving and paintings on medieval Scandinavian shields, armor, and talismans as a way to grant strength and bravery, and their exploits being told in great sagas.
The Maasai of Kenya singing traditional songs about the heroic gem warriors of ages past.
Depictions of female saints from medieval Roman Catholic churches and documents that look particularly otherworldly and all too familiar that just happen to fit the gems descriptions almost perfectly.
I need this to show up in canon, even if just as a passing nod like the painted portrait of the gems circa 17-18th century in Amethyst’s room.